| 摘要 |
PURPOSE:To simplify a drive circuit for a needle electrode and at the same time, eliminate a series/parallel conversion circuit by providing a photoelectric element to perform switching operation through the reception of a light by a circuit between the needle electrode and a high voltage power supply, and also a light source which projects light to the photoelectric element based on printing data. CONSTITUTION:A plurality of photoelectric elements 1, 1... are mounted independently after division on a common electrode 3 connected to a high voltage power supply 9, and a needle electrode is provided to each photoelectric element 1. After this, a plurality of needle electrodes 2, 2... are arranged in a row. The photoelectric element 1 shows a high resistance in the dark, and an optical semiconductor through which a photocurrent flows when a light is irradiated. In more concrete terms, amorphous silicon, selenium, etc., are used. A high voltage power supply is connected to the common electrode 3, and if a light is irradiated to the photoelectric element 1, a photocurrent flows therein, which applying high voltage to the needle electrode 2. A plurality of needle electrodes are aligned and the photoelectric elements 1 to be connected to the needle electrodes need not be separated by each element. If a light is projected to the neighborhood in which the needle electrodes 2 are connected, a monolithic photoelectric element capable of applying voltage to the needle only during the light projection may be used. |
